U.S. Pat. No. 5,879,827, the disclosure of which is incorporated herein by reference, discloses nanostructured elements comprising acicular microstructured support whiskers bearing acicular nanoscopic catalyst particles. The catalyst particles may comprise alternating layers of different catalyst materials which may differ in composition, in degree of alloying or in degree of crystallinity.
U.S. Pat. App. Pub. No. 2002/0004453 A1, now U.S. Pat. No. 6,482,763, the disclosure of which is incorporated herein by reference, discloses fuel cell electrode catalysts comprising alternating platinum-containing layers and layers containing suboxides of a second metal that display an early onset of CO oxidation.
U.S. Pat. Nos. 5,338,430, 5,879,828, 6,040,077 and 6,319,293, the disclosures of which are incorporated herein by reference, also concern nanostructured thin film catalysts.
U.S. Pat. Nos. 4,812,352, 5,039,561, 5,176,786, and 5,336,558, the disclosures of which are incorporated herein by reference, concern microstructures.
U.S. patent application Ser. No. 10/674,594, the disclosure of which is incorporated herein by reference, discloses fuel cell cathode catalysts comprising nanostructures formed by depositing alternating layers of platinum and a second layer onto a microstructure support, which may form a ternary catalyst.
U.S. patent application Ser. Nos. 10/945,178 and 10/944,998, the disclosures of which are incorporated herein by reference, discloses fuel cell membrane electrode assemblies and fuel cell polymer electrolyte membranes comprising bound anionic functional groups and Mn or Ru cations or comprising manganese oxides which demonstrate increased durability.
Ludvigson, J. Mater. Chem., 11 (2001) 1269-1276; Michas, J. Membrane Sci., 29 (1986) 239-257 and Japanese Kokai 2001/118591 (Morimoto) purportedly disclose polymer electrolyte membranes made by a method generally described as immersion of a membrane in a solution of a metal salt followed by an oxidization step to convert the metal salts into metal oxides in the finished product. The metal salts include Mn salts (in Ludvigson) and Ru salts (in Michas and Morimoto).
U.S. Pat. No. 6,335,112 (Asukabe) purportedly discloses a polymer electrolyte membrane comprising a hydrocarbon-based solid polymer electrolyte which contains a catalyst, which may be one of several catalysts including MnO2.
U.S. Pat. App. Pub. No. US 2003/0008196 A1 (Wessel) purportedly discloses the use of at least one additive in or on electrodes of a fuel cell, where the additive purportedly serves for the prevention of the formation and/or for the destruction of peroxides on or in the electrodes.